/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2015 Alejandro P. Revilla
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.jpos.iso.channel;

import org.jpos.iso.*;
import org.jpos.iso.packager.XMLPackager;

import java.io.BufferedReader;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * Implements an ISOChannel able to exchange <b>jPOS generated</b> (or
 * compliant) XML based ISO-8583 messages through a Telnet session the telnet
 * commands are simply ignored.
 *
 * @author <a href="mailto:apr@cs.com.uy">Alejandro P. Revilla</a>
 * @author <a href="mailto:marksalter@talktalk.net">Mark Salter</a>
 * @version $Id: TelnetXMLChannel.java 2594 2008-01-22 16:41:31Z apr $
 * @see ISOMsg
 * @see ISOException
 * @see ISOChannel
 */
public class TelnetXMLChannel extends BaseChannel {
	BufferedReader reader = null;

	static final String isomsgStartTag = "<" + XMLPackager.ISOMSG_TAG + ">";
	static final String isomsgEndTag = "</" + XMLPackager.ISOMSG_TAG + ">";

	/**
	 * Public constructor (used by Class.forName("...").newInstance())
	 */
	public TelnetXMLChannel() {
		super();
	}

	/**
	 * Constructs client ISOChannel
	 *
	 * @param host server TCP Address
	 * @param port server port number
	 * @param p    an ISOPackager
	 * @see ISOPackager
	 */
	public TelnetXMLChannel(String host, int port, ISOPackager p) {
		super(host, port, p);
	}

	/**
	 * Construct server ISOChannel
	 *
	 * @param p an ISOPackager
	 * @throws IOException
	 * @see ISOPackager
	 */
	public TelnetXMLChannel(ISOPackager p) throws IOException {
		super(p);
	}

	/**
	 * constructs a server ISOChannel associated with a Server Socket
	 *
	 * @param p            an ISOPackager
	 * @param serverSocket where to accept a connection
	 * @throws IOException
	 * @see ISOPackager
	 */
	public TelnetXMLChannel(ISOPackager p, ServerSocket serverSocket)
			throws IOException {
		super(p, serverSocket);
	}

	/**
	 * @return a byte array with the received message
	 * @throws IOException
	 */
	protected byte[] streamReceive() throws IOException {
		int sp = 0;
		StringBuilder sb = new StringBuilder();
		while (reader != null) {
	        /*
             * Throw away any telnet commands - each is 3 bytes first being
             * x'FF'...
             */
			reader.mark(3); // Mark the current position in case there are no
			// telnet commands (FFnnmm)
			while (reader.read() == 255) {
				reader.skip(2);
				reader.mark(3);
			}
			reader.reset(); // Return to the first byte that was *not* a telnet
			// command (IAC).

			// Now the commands are out of the way continue with the xml stream
			// until it closes with </isomsg>.
			String s = reader.readLine();
			if (s == null)
				throw new EOFException();
			int isomsgStart = s.indexOf(isomsgStartTag);
			if (isomsgStart >= 0) {
				sp++;
				sb.append(s, isomsgStart, s.length() - isomsgStart);
			} else {
				int isomsgEnd = s.indexOf(isomsgEndTag);
				if (isomsgEnd >= 0) {
					sb.append(s, 0, isomsgEnd + isomsgEndTag.length());
					if (--sp <= 0)
						break;
				} else {
					if (sp > 0)
						sb.append(s);
				}
			}

		}
		return sb.toString().getBytes();
	}

	protected int getHeaderLength() {
		// XML Channel does not support header
		return 0;
	}

	protected void sendMessageHeader(ISOMsg m, int len) {
		// XML Channel does not support header
	}

	protected void connect(Socket socket) throws IOException {
		super.connect(socket);
		reader = new BufferedReader(new InputStreamReader(serverIn));
	}

	public void disconnect() throws IOException {
		super.disconnect();
		if (reader != null)
			reader.close();
		reader = null;
	}
}
